This invention relates to apparatus and methods for providing effective exhaustive ventilation for proximity ventilated cooking systems.
In self-ventilated cooking systems, such as cooktops and grill ranges with proximity ventilation, cooking gases, vapors and odors are drawn into an exhaust inlet and are exhausted into the atmosphere. Usually, the exhaust inlet is located adjacent the cooking surface and is the inlet to a flow path which serially includes a plenum, a blower, an atmospheric exhaust and interconnecting ductwork. The flow path to the atmosphere normally extends through a wall or floor of the room in which the cooking system is located.
The blower is frequently made a separate unit from the rest of the cooking apparatus and is installed prior to the installation of the rest of the apparatus. The blower is provided with a pair of brackets which permit the selective mounting of the blower to the floor for discharge either through-the-wall or through-the floor, as required by the installation. Because the blower is installed separately, it can be located for ease of access and to avoid the joists or studs, which can be a problem in retrofit installations. For a through-the-floor exhaust, the blower is secured to the floor with the outlet extending through the floor. However, for a through-the-wall installation, the blower is secured to the floor with the outlet of the blower extending horizontally. The outlet of the blower is connected to atmosphere by a flexible ductwork which extends through the wall to an external exhaust outlet. After the blower is secured in place and connected to the atmospheric exhaust, the self-ventilated cooking apparatus is set in place over the blower and connected to the electrical service. The self-ventilated cooking apparatus can have a full height plenum, which can be made thinner to accommodate a full size oven, or to permit the installation of a full size oven where the cooking surface is adapted for countertop installation, while still providing proximity ventilation of the cooktop. The flow path is completed by connecting the blower and the plenum of the range by means of a length of flexible pipe, and the blower is plugged into the self-ventilated cooking apparatus and thereby the electrical system of the apparatus. Such self-ventilated cooking systems are disclosed in U.S. Pat. No. 4,428,357.
The installation of such cooking systems in a building presents significant problems. The air flow path from the blower to atmosphere varies widely from building to building in its length and its effective resistance to air flow. In some buildings, the air flow path may be long and torturous while in other buildings, the air flow path may be short and free from restrictions. Such variations in the air flow path have limited the installation of such cooking systems, particularly where gas was used to provide heat for grilling and cooking. Where the exhaust paths were short and free from restrictions, such systems provided too much air flow at the cooking surface and did not provide uniform cooking and heat distribution and, where gas heat was used, proper flame formation and combustion. Where the exhaust paths were long or torturous, the system provided too little air flow at the cooking surface and was ineffective in capturing cooking gases and vapors and in carrying grease particles to atmosphere. Variations in the structure of buildings and in the length and complication of the exhaust path between the blower and atmosphere through the walls of the building could therefore produce ineffective exhaustive ventilation.